The piezoacoustic resonator is a piezoacoustic thin-film resonator (Film Bulk Acoustic resonator or FBAR), for example. A thin-film resonator of this type is described in WO 2004/017063 A2, for example. The thin-film resonator consists, for example, of two electrode layers and a piezoelectric layer arranged between the electrode layers in the form of a piezoceramic layer. The piezoceramic layer is a polycrystalline layer made up of zinc oxide monocrystals. The electrode layers are made of platinum, for example. The electrode layers and the piezoceramic layer are arranged in relation to one another in such a way that an electrical activation of the electrode layers by means of an electrical alternating field leads to an oscillation of the resonator. Activating the arrangement by means of a specific electrical alternating field results in a resonance oscillation at a specific resonance frequency. The resonance frequency of the oscillation is dependent inter alia on the layer thicknesses of the layers. Owing to an orientation of the zinc oxide monocrystals the thin-film resonator can be excited into longitudinal thickness mode oscillations and shear thickness mode oscillations.
In order to produce the layers of the thin-film resonator on the substrate, for example a silicon substrate, a vapor deposition method (deposition from the gas phase) is performed. An evaluation device is integrated in the substrate for the purpose of determining the resonance frequency. In this background art it is not disclosed how the evaluation device is brought into electrical contact with the electrode layers of the thin-film resonator.